A communications network allows a large group of widely-distributed users to communicate with one another. A network includes a variety of devices, connected together through a variety of media types, that work together to connect any user on the network with any other user.
Software-defined networking (SDN) allows network services to be managed by abstracting lower-level functions. An SDN controlled network divides network functionality into two components—a control plane and a data plane.
The control plane handles decisions about where data traffic is to be sent, while the data plane provides the underlying network components that forward the data traffic to destinations decided upon by the control plane. The control plane takes action through use of source and destination addresses and selects efficient paths through the network.
The control plane includes components such as controllers and orchestrators. The data plane includes components such as switches, routers and other network elements (referred to herein as NEs)
In legacy systems, the control plane and the data plane of a network generally exist within the same hardware. For example, switches and routers, two examples of network elements, typically provided both control plane and data plane functionality. Such network elements may analyze data packets as they are received to extract control plane (e.g., communications path) information, and use that information to convey the associated information along a proper media path.